In the field of consumer products, it is desirable to be able to produce products that have an attractive and sometimes unusual appearance that will appeal to consumers. It is also desirable to produce products which have interesting taste and texture combinations that will also appeal to the consumer. This latter requirement has lead to the development of filled products in which a filling is contained in an outer casing formed from a different material.
It is known to produce food products comprising an outer casing made from a first food material which contains a filling of a second food material. A wide variety of food products are produced in this way from a range of food materials. Often, the outer casing will be made from a food material which is substantially solid at normal room temperature (20° C. to 25° C.) and pressure but which may be heated or otherwise processed to place it in a flowable, plastic or clay-like state in order that the material can be shaped. After shaping, the material is allowed to solidify so as to retain the shape and to contain the filling material. A food material of this nature will be referred to herein generally as being “solidifyable” and terms such as “solidifyable material”, “solidifyable food material” and “solidifyable confectionery material” should be construed accordingly.
A variety of food materials can be used as fillings, including solidifyable food materials. However, materials which remain in a flowable state at normal room temperature and pressure are often used as fillings. These include, but are not limited to, liquid and semi-liquid fillings, soft centres and more viscous materials that will retain their shape but which are malleable to the touch, such as gums. A food material which remains in a flowable state at room temperature will be referred to herein generally as being “flowable” and terms such as “flowable material”, “flowable food material and “flowable confectionery material” should be construed accordingly. The term ‘flowable” as used herein may include solutions, suspensions, emulsions, semi-solids, creams, gels, etc, that may not be completely liquid, within its meaning. As used herein, the term ‘liquid’ refers to substances which will readily flow or maintain fluid properties at room temperature and pressure.
Filled confectionery products are particularly popular and have been produced with casings made from a wide variety confectionery materials including, but not limited to, sugar based candies and fat-containing confectionery materials such as chocolate. Chocolate is a confectionery foodstuff usually formed from one or more components of the cocoa bean. In particular, chocolate is usually formed from solids from cocoa beans, including fats, such as cocoa butter, and a sweetener such as sugar. The taste of the chocolate is typically determined by the quantity and type of fat and sweetener present, as well as the presence of other ingredients such as flavourings. A typical commercial dark chocolate will normally comprise non-fat cocoa solids, fat, sugar and optionally an emulsifier. A typical commercial milk chocolate will normally comprise non-fat cocoa solids, fat, milk solids, sugar and optionally an emulsifier. A typical commercial white chocolate will normally comprise milk solids, cocoa butter or other fat, sugar and optionally an emulsifier.
Examples of typical materials that have been used as fillings in confectionery products include: liqueurs, honey, toffee, caramel, cream, fondants, praline, fudge, gels, confectionery emulsions, jelly, jam and the like.
Filled confectionery products have been produced in a variety of different shapes and sizes and using various methods. Typically though, confectionery products filled with a flowable confectionery material are produced by moulding, such as shell-moulding or book-moulding, or by so-called “one shot” centre-in-shell depositing.
A convenient method of manufacturing elongate food products is by means of extrusion. In this method, a food material is forced through an extrusion die in a flowable, plastic or clay-like state to produce an extrudate body having a substantially constant cross section. The extrudate body is subsequent is cut into lengths and may be subjected to further processing.
One approach for producing an elongate filled chocolate confectionery product by means of extrusion is disclosed in GB 223,362. In the method described, a tubular casing of chocolate is formed by extrusion. After forming, the tube is cut into lengths and one end of each length is closed. A filling is introduced though the open end of each length before the second end is closed. The apparatus and method described GB 223, 362 is relatively complex, involving several different process steps which must be undertaken to produce the final filled product.
EP 1 166 640 A1 discloses a co-extruded confectionery product in which a fat-containing confectionery material, such as chocolate, is extruded to form a hollow or tubular form surrounding a filling of another confectionery material. However, the method disclosed is only suitable for use where the filling material does not flow when the extrudate body is cut.
Foodstuffs in general tend to be more difficult to extrude than non-foodstuffs and especially plastics and rubbers/elastomers. Handling foodstuffs gives rise to difficulties due in part to need to ensure that they are not contaminated and also that the process itself does not adversely affect the taste and/or texture of the material. For example, whilst many non-food materials can be processed at elevated temperatures, this may not be possible with certain foodstuffs. Food materials may also have non-uniform textures and/or viscosity differences within the same product batch. In contrast, non-food materials can usually be processed prior to extrusion to ensure uniform and consistent texture and/or viscosity. These issues give rise to particular problems when attempting to extrude food materials that are not met when extruding non-food materials. Accordingly, apparatus and methods used to extrude non-food materials such as plastics or rubbers/elastomers are often not suitable for extruding food materials. Extruding chocolate is particularly problematical and is rarely carried out in practice because of its low viscosity when liquid. At elevated temperatures the cocoa butter in chocolate becomes melted and flows easily. If liquid chocolate is extruded it is generally too thin to retain the extruded shape, unlike more viscous materials such as meat or dough. The above problems have meant that other, less efficient, processes such as moulding have to be used where the shape of the product is not suited to manufacture using the known extrusion apparatus and methods or the extruded product has to be subjected to further shaping processes. Attempts to co-extrude confectionery products and other food products with a flowable filling have proven particularly difficult because there is a tendency for the filling material to leak from the ends when the extrudate body is cut. Even where the filling material is not flowable, the results of co-extrusion are not always satisfactory as the filling material is visible at the ends of the product. Where this is not desirable, the product must be subjected to further processing to apply a coating over, or to otherwise cover, the cut ends.
Products other than food products can also be produced by means of co-extrusion to have an outer casing made from a first material which contains a filling of a second material and similar problems to those discussed above arise, particularly where the second material is a flowable material.
There is a need then for improved methods and apparatus for producing filled products which overcome, or at least mitigate, some or all of the limitations of the previously known apparatus and methods.
There is in particular a need for improved methods and apparatus for producing filled food and more especially filled confectionery product which overcome, or at least mitigates, some or all of the limitations of the previously known apparatus and methods.